Researchers at the Center for Infection and Immunity at Columbia University's Mailman School of Public Health identified distinct immune changes in patients diagnosed with chronic fatigue syndrome, known medically as myalgic ...

New research from scientists at the Keck School of Medicine of the University of Southern California (USC) shows that the body's immune system may be able to clear the brain of toxic plaque build-up that ...

UT Southwestern Medical Center researchers have identified a common signaling mechanism to produce interferon - one of the main proteins used to signal the immune system when the body needs to defend itself against a virus, ...

A short nap can help relieve stress and bolster the immune systems of men who slept only two hours the previous night, according to a new study published in the Endocrine Society's Journal of Clinical Endocrinology & Metabolism (JCEM) ...

A team of international scientists has discovered a new mechanism by which immune cells in the skin function act as the body's 'border control', revealing how these cells sense whether lipid or fat-like molecules ...

Stem cell transplants may be more effective than the drug mitoxantrone for people with severe cases of multiple sclerosis (MS), according to a new study published in the February 11, 2015, online issue of ...

Hot on the heels of discovering a protective form of immune response to spinal cord injury, researchers at the University of Virginia School of Medicine have pinpointed the biological trigger for that response - a vital step ...

Several drugs now used to treat cancer and autoimmune diseases are actually repurposed tools derived from the immune system. One of the ways these "therapeutic antibodies" work is to grab onto malignant or ...

Scientists from the CNRS, INSERM and Université de Limoges, working in the Laboratoire Contrôle de la Réponse Immune B et Lymphoproliférations (CNRS/Université de Limoges) have demonstrated that the ...

Research led by St. Jude Children's Research Hospital scientists has identified a potential target in the quest to develop a more effective treatment for leishmaniasis, a parasitic tropical disease that kills ...

A third of all humans carry the parasite that causes toxoplasmosis—a disease commonly associated with cats, HIV-AIDS patients and pregnant women—with scientists long believing healthy immune systems control the parasite ...

Immune system

An immune system is a collection of biological processes within an organism that protects against disease by identifying and killing pathogens and tumour cells. It detects a wide variety of agents, from viruses to parasitic worms, and needs to distinguish them from the organism's own healthy cells and tissues in order to function properly. Detection is complicated as pathogens can evolve rapidly, producing adaptations that avoid the immune system and allow the pathogens to successfully infect their hosts.

To survive this challenge, multiple mechanisms evolved that recognize and neutralize pathogens. Even simple unicellular organisms such as bacteria possess enzyme systems that protect against viral infections. Other basic immune mechanisms evolved in ancient eukaryotes and remain in their modern descendants, such as plants, fish, reptiles, and insects. These mechanisms include antimicrobial peptides called defensins, phagocytosis, and the complement system. Vertebrates such as humans have even more sophisticated defense mechanisms. The immune systems of vertebrates consist of many types of proteins, cells, organs, and tissues, which interact in an elaborate and dynamic network. As part of this more complex immune response, the human immune system adapts over time to recognise specific pathogens more efficiently. This adaptation process is referred to as "adaptive immunity" or "acquired immunity" and creates immunological memory. Immunological memory created from a primary response to a specific pathogen, provides an enhanced response to secondary encounters with that same, specific pathogen. This process of acquired immunity is the basis of vaccination.

Disorders in the immune system can result in disease. Immunodeficiency occurs when the immune system is less active than normal, resulting in recurring and life-threatening infections. Immunodeficiency can either be the result of a genetic disease, such as severe combined immunodeficiency, or be produced by pharmaceuticals or an infection, such as the acquired immune deficiency syndrome (AIDS) that is caused by the retrovirus HIV. In contrast, autoimmune diseases result from a hyperactive immune system attacking normal tissues as if they were foreign organisms. Common autoimmune diseases include Hashimoto's Thyroiditis, rheumatoid arthritis, diabetes mellitus type 1 and lupus erythematosus. Immunology covers the study of all aspects of the immune system which has significant relevance to human health and diseases. Further investigation in this field is expected to play a serious role in promotion of health and treatment of diseases.